Dust filter bag for a vacuum cleaner

Abstract

A dust filter bag (1) for a vacuum cleaner (3), with a retaining plate (H). The bag is constructed of a solid paper material, such as cardboard for example, to which a dust bag (12) is joined, for example adhesively, with a closure flap (13) turned towards the inside (15) of the dust bag (12), hinged on the retaining plate (H), which closure flap (13) is openable against a spring action and, in closed condition, keeps closed an opening (O) in the retaining plate (H). To make the dust filter bag simpler in construction and more advantageous as regards use, a band-like spring element (F) is attached to the closure flap (13) in such a way that, in the closed condition (FIG. 4), there is formed a clearance (Y) between a band end (E--E) and a hinge axis (14), lying outside of the band, of the closure flap (13), where the hinge axis (14) is provided turned towards the inside (15) of the dust bag (1).

We claim: 
     
       1. A dust bag for a vacuum cleaner, with a retaining plate comprising a stiff paper material to which a dust bag is joined with a closure flap turned towards the inside of the dust bag, hinged on the retaining plate, which closure flap is openable against a spring action and, in its closed condition, keeps closed an opening in the retaining plate, characterised in that a spring element formed as a layer element is arranged on the closure flap in such a way that, in a closed position, of the closure flap there is formed a clearance between a band plane and a hinge axis of the closure flap, lying outside of the band, where the hinge axis is arranged turned towards the inside of the dust bag. 
     
     
       2. A dust filter bag according to claim 1, characterised in that the spring element is attached to an outwards-turned first surface of the closure flap. 
     
     
       3. A dust filter bag according to claim 1, characterised in that the spring element continues into an edge seal of the closure flap. 
     
     
       4. A dust filter bag according to claim 2, wherein the spring element is formed as a layer element substantially fully overlapping the surface. 
     
     
       5. A dust filter bag according to claim 1, characterised in that on the retaining plate, there is provided a bearing surface adapted to the profile of the closure flap. 
     
     
       6. A dust filter bag according to claim 1, characterised in that the spring element is an elastic element and, in resiliently extended condition in the closed position of the closure flap, connects the latter to the retaining plate. 
     
     
       7. A dust filter bag according to claim 1, characterised in that the band element has a preloading corresponding to approximately 10% of the elastic extension reserve, in a closed position of the closure flap. 
     
     
       8. A dust filter bag according to claim 7, characterised in that the preloading is achieved by a bulge transverse to the direction of extension of the spring element. 
     
     
       9. A dust filter bag according to claim 1, characterised in that the spring element is held between two layers of the retaining plate. 
     
     
       10. A dust filter bag according to claim 1, characterised in that the spring element has a greater width than that of the region of the hinge-forming cooperation between closure flap and retaining plate. 
     
     
       11. A dust filter bag according to claim 5, characterised in that the stiff paper material at the bearing surface of the closure flap is treated or coated for greater smoothness. 
     
     
       12. A dust filter bag according to claim 5, characterised in that the bearing surface is imprinted. 
     
     
       13. A dust filter bag according to claim 1, characterised in that the retaining plate has on its outer side, in the region of the opening, a sealing surface for engagement of an axially aligned end face of a vacuum-cleaner blower connection piece. 
     
     
       14. A dust filter bag according to claim 1, further comprising a slide, and wherein the opening is additionally slidably closable by the slide. 
     
     
       15. A dust filter bag according to claim 14, characterised in that between the slide and the closure flap, there is formed, in the retaining plate, an intermediate plate, in which the opening is located. 
     
     
       16. A vacuum cleaner with a blower, a vacuum-cleaner blower connection piece and an accommodating space for the dust filter bag, where the vacuum-cleaner blower connection piece is formed for end-on engagement with a dust filter bag accommodated in the accommodating space, in particular a dust filter bag according to claim 1, characterised in that an engagement face of the blower connection piece is provided with a double ring seal. 
     
     
       17. A dust filter bag according to claim 16, characterised in that a chamber formed on engagement between the sealing lips of the double ring seal and the retaining plate has a passage for connection to the atmosphere. 
     
     
       18. A dust filter bag according to claim 17, characterised in that the passage is defined by ducts. 
     
     
       19. A dust filter bag according to claim 17, characterised in that the passage is defined by an unskinned portion of an open-pored foamed plastic. 
     
     
       20. A dust filter bag according to claim 13, further comprising a double ring seal, wherein the blower connection piece has, on the end face, an annular groove to accommodate the double ring seal, and a groove base of the groove has a break-through connecting to the outer surface. 
     
     
       21. A dust filter bag according to claim 1, characterised in that the retaining plate has, in the region of its hinge axis, a deflecting edge projecting over the edge of the closure flap. 
     
     
       22. A dust filter bag according to claim 1, wherein the retaining plate comprises a base plate, a frame portion placed on the base plate, a slide on the base plate and slideable in the frame portion which defines a guide shaft, as well as a cover plate, where, further, the cover plate has a window for reaching through to a handling end of the slide, and wherein the slide has a smoothly formed face which is smooth relative to a surface of the stiff paper material, and rests with this face on a likewise smoothly formed face of the cover plate. 
     
     
       23. A dust filter bag according to claim 22, wherein the base plate has a smoothly formed face which is smooth relative to a surface of the stiff paper material, and the rear side of the slide is turned towards the smoothly formed face of the base plate. 
     
     
       24. A dust filter bag according to claim 22, wherein the outwards-turned, face-side handling end of the slide is rough compared to its smoothly formed face and carries a slide entraining projection, which, with its rough face, points outwards. 
     
     
       25. A dust filter bag according to claim 22, characterised in that the slide has a leaf-shaped outline comprising a planar body with a first relatively broad portion and a second relatively narrow portion extending from the first portion. 
     
     
       26. A dust filter bag according to claim 25, wherein the second relatively narrow portion of the slide has the form of a leaf-stalk and serves as a handling end, the handling end tapers towards its free end carrying the slide entraining projection, and the stalk-guiding portion of a slide guide shaft corresponds to an outline of the leaf-stalk. 
     
     
       27. A dust filter bag according to claim 26, characterised in that the window too is formed as an aperture corresponding to the stalk outline. 
     
     
       28. A dust filter bag according to claim 24, characterised in that the slide entraining projection projecting into the window corresponds, in respect of its edges lying in the direction of sliding, to the taper of the window.